1 Field of the Invention
This invention relates to roll compensation systems for radar mounted in aircraft and particularly to an electronic roll compensation system for use in a silent lobing type of radar that provides lobing of the received signals.
2. Description of the Prior Art
Conventionally, radar compensation of aircraft angular roll is provided by mechanical stabilizing systems which operate so that the antenna angular roll position relative to the ground does not change with any aircraft roll angle. However, in these stabilized systems, separate gimbal and drive systems are thus required in addition to those needed for scanning. The gimbal and drive systems required for the mechanical antenna stabilization add considerable weight and complexity to the aircraft installation. Although the exact amount of weight increase varies according to the particular equipment, typical increases are on the order of 20 pounds. Another problem is that the additional gimbal required for roll stabilization also increases the size of the overall antenna assembly with the result that within a given installation space, the area of the radiating portion of the antenna and consequently the antenna gain must be reduced. It would be a substantial advance to the art if it were possible to achieve the required antenna stabilization without adding appreciable weight to the equipment and without any substantial reduction of available antenna space and antenna gain.